Fig. 2. Comparison of microbial community composition and biomass in surface soil and an integrated soil column, with microbial community composition assessed as (a) position on principal component analysis (PCA) Axis 1, (b) fungal/bacterial ratio, (c) arbuscular mycorrhizal fungal (AMF)/bacterial ratio, (d) Gram positive/Gram negative ratio, (e) actinomycetal/bacterial ratio, and (f) microbial biomass assessed as total phospholipid fatty acid (PLFA). Each point represents the mean (with standard deviation) of three replicate measures. The dotted line is a 1:1 line: points that fall above the 1:1 line are higher in the integrated than surface soil, while points that fall below the 1:1 line are higher in the surface than integrated soil column.